Machines for washing beer kegs and like containers

ABSTRACT

A MACHINE FOR AUTOMATICALLY WASHING BEER KEGS OR LIKE CONTAINERS COMPRISES A HEAD WHICH IS ARRANGED TO BE APPLIED TO THE BUNG HOLE OR OTHER OPENING OF THE CONTAINER AND WHICH HAS AN INLET PASSAGE FOR THE SUPPLY OF WASHING LIQUID TO THE CONTAINER AND FOR THE SUPPLY OF STEAM OR GAS UNDER PRESSURE AND AN OUTLET PASSAGE OUT OF WHICH LIQUID SUPPLIED TO THE CONTAINER IS BLOWN BY THE STEAM OR GAS, THE SUPPLY OF LIQUID AND GAS OR STEAM AND OTHER OPERATIONS OF THE MACHINE BEING CONTROLLED BY A CONTROL DEVICE. THE CONTROL DEVICE IS CONNECTED TO A LIQUID DETECTOR WHICH IS IN COMMUNICATION WITH THE OUTLET PASSAGE, SUCH THAT AFTER THE SUPPLY OF WASHING LIQUID AND THE SUBSEQUENT SUPPLY OF GAS OR STREAM, THE DETECTOR CAUSES THE CONTROL DEVICE TO INITIATE A FURTHER OPERATION OF THE MACHINE ONLY WHEN THE DETECTOR DETECTS THE ABSENCE OF WASHING LIQUID IN THE OUTLET PASSAGE. THE DETECTOR IS AN ELECTRICAL DEVICE WHICH IS SENSITIVE TO THE ELECTRICAL CONDUCTIVITY OF THE FLUID FLOWING THROUGH THE OUTLET PASSAGE, THE CONDUCTIVITY OF LIQUID BEING GREATER THAN THE CONDUCTIVITY OF STEAM OR GAS.

Feb. 16, 1971 M. RUDDIQK 3,564,584

MACHINES FOR WASHING BEER KEGS AND LIKE CONTAINERS Filed Aug. 12, 1968 i ILIZ/ 25 United States Patent 01 flee 3,564,584 Patented Feb. 16, 1971 3,564,584 MACHINES FOR WASHING BEER KEGS AND LHCE CONTAINERS Maurice Ruddick, Rochester, Kent, England, assignor to Burnett & Rolfe Limited, Rochester, England, a British company Filed Aug. 12, 1968, Ser. No. 751,858 Claims priority, application Great Britain, Aug. 18, 1967, 38,125/ 67 The portion of the term of the patent subsequent to July 8, 1985, has been disclaimed Int. Cl. B08b 3/10, 9/14 US. Cl. 134-57 3 Claims ABSTRACT OF THE DISCLOSURE A machine for automatically washing beer kegs or like containers comprises a head which is arranged to be ap plied to the bung hole or other opening of the container and which has an inlet passage for the supply of washing liquid to the container and for the supply of steam or gas under pressure and an outlet passage out of which liquid supplied to the container is blown by the steam or gas, the supply of liquid and gas or steam and other operations of the machine being controlled by a control device. The control device is connected to a liquid detector which is in communication with the outlet passage, such that after the supply of washing liquid and the subsequent supply of gas or stream, the detector causes the control device to initiate a further operation of the machine only when the detector detects the absence of washing liquid in the outlet passage. The detector is an electrical device which is sensitive to the electrical conductivity of the fluid flowing through the outlet passage, the conductivity of liquid being greater than the conductivity of steam or gas.

Kegs or like containers which are usually made of metal, are now generally used for holding beer and other liquids and these containers are washed after use and subsequently refilled in a brewery or other place by means of automatic machinery.

In the usual kind of washing machine, a head is applied to the bung hole or other opening of the container and this head has two passages through it. One is a drain passage and through the other, washing liquid is supplied and subsequently gas, usually air, under pressure or steam under pressure is supplied to blow out the washing liquid through the drain passage. The cycle of supply of washing liquid and the subsequent supply of gas or steam to blow out the washing liquid may be repeated a number of times.

In the past, such washing machines have been controlled -by a control device operated by a timer. During the course of the washing operation, washing liquid is supplied through the passage through the head for a predetermined time and subsequently steam or gas under pressure is supplied, also for a predetermined time interval, to blow the washing liquid out through the drain passage. This arrangement is not, however, very satisfactory because if for any reason the flow of the washing liquid out of the container is impeded, for example by blocking or partial blocking of the drain passage, some washing liquid may remain in the container. If at the end of the washing operation the container is then discharged from the machine and conveyed to a filling machine, the washing liquid will be mixed with the beer or other potable liquid with which the container is filled.

With the aim of overcoming this difficulty, according to this invention, a machine for automatically washing beer kegs or like containers comprises a head which is arranged tobe applied to the bung hole or other opening of the container, the head having an inlet passage for the supply of Washing liquid to the container and for the supply of steam or gas under pressure and an outlet passage out of which liquid supplied to the container is blown by the steam or gas under pressure, the supply of liquid and gas or steam and other operations of the machine, for example discharge of a container from the machine, being controlled by a control device which is connected to a liquid detector in communication with the outlet passage, the arrangement being that after the supply of Washing liquid and the subsequent supply of gas or steam, the detector causes the control device to initiate a further operation of the machine only when the detector detects the absence of washing liquid in the outlet passage.

Thus it will be seen that by the provision of the detector in the outlet passage, instead of a timer for operating the control device, the possibility of the machine continuing to operate whilst washing liquid is left in the container and the discharge of the container from the machine under these conditions is entirely prevented.

Washing machines in accordance with the invention may be made suitable for use with kegs with openings containing no permanent fittings, but metal beer kegs are nowadays frequently provided with a tubular spear through which the beer is supplied to the keg, and, subsequently, is forced out of the keg by the application of a top gas pressure to the beer in the keg and machines in accordance with the invention can readily be used with these kegs. With kegs of this kind, the opening is in the top of the keg and the spear extends almost to the bottom. The machine is then arranged to wash the keg in an inverted position and the head is constructed so that the Washing liquid and gas or steam supply passage communicates with the inside of the spear and the outlet passage communicates with the space within the container outside the spear. Thus, in use, Washing liquid is supplied upwards to what is normally the bottom of the inverted container and the washing liquid is blown out of what is normally the top of the container.

Various forms of detectors may be used for detecting the presence or absence of liquid in the outlet passage. The detector preferably takes the form of an electrical probe by which the conductivity of the fluid surrounding the probe within a housing is measured, or alternatively in which there are two probes and the conductivity or dielectric properties of the fluid between the probes is measured. The conductivity of washing liquid in the outlet passage is greater than the conductivity of steam or air flowing through the passage and thus the electrical probe or probes indicate a drop in conductivity when the flow of washing liquid past them is replaced by a flow of steam or air. An electrical circuit controlled in dependence upon this conductivity then operates the control device to initiate the next operation of the machine.

As an alternative to the probe or probes, the detector may take the form of an orifice in the outlet passage with a device for measuring the difference of pressure between the two sides of the orifice. When liquid is flowing through the orfice, there is a higher pressure drop across the orifice than when air or steam is flowing through it. Thus when the pressure differential drops, there is an indication that the flow of washing liquid has ceased and the differential pressure measurement device operates the controller.

Another possibility is the provision of a hinged vane or plate in the outlet passage. This vane or plate is deflected by the flow of fluid past it, but a smaller deflection is caused by a flow of air or steam than that caused by a flow of washing liquid. In this case, a sudden drop in the deflection of the vane or plate brings about the operation of the control device.

Similarly a rotary flow meter may differentiate between the flow of a liquid and a gas or vapour.

Part of an example of a machine in accordance with the present invention is illustrated diagrammatically in the accompanying drawings, in which:

FIG. 1 is a section showing the head connected to a container which is being washed, and showing the inlet and outlet passages of the head and the liquid detector in the outlet passage; and,

FIG. 2 is a diagram of an electrical circuit which forms part of the liquid detector.

FIG. 1 shows an inverted beer keg 1 with the neck 2 of its bung hole connected to the washing head 3 of a washing machine in accordance with the present invention, and with the keg 1 about to be washed. The keg 1 is of the kind which has an internal spear 4 which is mounted so that it can move upwards and downwards through a limited distance through an internal skirt 5 which extends from the neck 2 into the inside of the keg 1. The end of the spear 4 within the neck 2 has a sealing ring 6 which is normally held by a spring against a seal 7 around the neck 2.

The head 3 has a socket 8 at its upper end and within this socket is a sealing ring 9. When the head 3 is moved into engagement with the keg 1, the neck 2 enters the socket 8 and a seal is formed between the sealing rings 7 and 9. Within the head 3 is a tube 10 which is slidable upwards and downwards and is connected to a piston in a pneumatic cylinder (not shown). Normally the tube 10 is biased downwards by a spring, but after the head 3 has been connected to the neck 2, the pneumatic cylinder is pressurised and the tube 10 is forced upwards. The upper end of the tube 10 seals against the sealing ring 6 on the end of the spear 4 and pushes the spear 4 upwards so that the ring 6 is moved out of engagement with the sealing ring 7 on the neck 2.

When the tube 10 is in its upper position, perforations 11 through its wall are in communication with a chamber 12 within the head 3 and there is communication from this chamber through the perforations 11, through the upper part of the tube 10 and through perforations 13 in the end of the spear 4 into the spear 4 itself, and hence through the far end of the spear 4 into the keg 1. There is also communication from a second chamber 14 within the head 3 through the clearance between the sealing rings 6 and 7 and through perforations 15 in the skirt 5 with the interior of the keg 1 outside the spear 4.

A duct 16 leads from the chamber 12 to a pipe 17 and forms a supply duct for the supply of washing liquid and steam through the spear 4 to the keg 1 and a duct 18 communicating with the chamber 14 forms a drainage duct and leads through a housing 19 to a drainage pipe 20.

The machine has means for moving the kegs 1 into position over the head 3 and for then moving the head 3 into connection with the neck 2 of the kegs 1. The

machine also has means for delivering steam, water, and detergent through the supply pipe 17, means connected to the drainage pipe 20 for recirculating detergent and discharging waste, water and steam. These means are not shown since they and their operation are exactly the same as are illustrated and described in detail in our copending application Ser. No. 675,541. The operation of the machine is controlled by a control device (not shown) which is similar to the sequence controller described in our application Ser. No. 675,541, now US. Pat. No. 3,454,018 and hence the washing cycle of the present machine is the same as that described in said application.

However, instead of a temperature sensitive probe sensing the temperature of the fluid flowing through the drainage duct of the head and controlling the sequence controller in dependence on the temperature, in the present machine a liquid detecting device 21 is used which senses the electrical conductivity of the fluid passing through the drainage duct 18 of the head 3. The detector 21 comprises a pair of electrically conducting probes 22 and 23 which project into the housing 19 so that fluid flowing from the drainage duct 18 to the drainage pipe 20 passes between the two probes 22 and 23. The probes 22 and .23 are respectively connected by leads 24 and 25 to terminals 26 and 27 across which a power source is applied. The lead 24 connects the probe 22 to the terminal 26 through the primary coil 28 of a transformer 29 and a variable resistor 30. The secondary coil 31 of the transformer 29 is connected by leads 32 and 33 through a controller (not shown) to the control device of the machine.

The current flowing through the primary circuit 28, and therefore the induced current flowing the secondary circuit 31 is dependent upon the conductivity of the fluid flowing between the probes 22 and 23. The conductivity of a liquid is much higher than the conductivity of steam of a gas, and therefore the current flowing through the circuits when liquid is flowing through the outlet duct 18 of the head 3 is greater than the current flowing through the circuits when steam is passing through the duct 18. The controller is set so that it produces a signal with a current at or below a predetermined current corresponding to a conductivity between that of liquids and of steam. As in our copending application Ser. No. 675,541 this signal is transmitted to the control device is arranged so that various of the operations which it controls are prevented from coming about until a signal has been received from the controller. Both the controller and the control device consist of solid state circuits with an electrically operated timer.

The washing cycle of the present example is controlled by the control device and is the same as the cycle described in our copending application Ser. No. 675,541

' and is as follows.

Firstly the head 3 is connected to the neck 2 of a keg 1 and the tube 10 in the head 3 is moved to open the passages communicating with the inside of the keg 1. Steam is then blown into the keg 1 through the supply duct 17 and the spear 4. If the keg 1 is empty of liquid, the steam blows through the drainage duct 18 and through the housing 19 so that the detector 21 measures a low conductivity and a signal is produced by the controller which causes the control device to continue to its next operation. At this operation, the steam supply is shut-off and water is supplied to the keg 1 to perform a pre-wash. After a predetermined time the water supply is shut-01f and steam is again supplied to the keg 1 to blow out the water. Whilst the water is flowing out, the conductivity measured by the detector 21 is such that no signal is produced by the controller and the control device is prevented from shutting off the supply of steam. As soon as the keg 1 is empty of water, the flow of steam over the probes 22 and 23 produces another signal from the controller which enables the control device to perform the next operation. This consists of supplying a metered volume of detergent from a storage tank (not shown) through the keg 1 and out of the drainage duct 20 to the recirculating means from which it is pumped back to the storage tank. After a predetermined time the supply of detergent is shut-01f and steam is again supplied to the keg 1. This supply of steam continues as before until all the detergent has been discharged from the keg 1 and passed back to the storage tank. When this has been done and steam passes over the probes 22 and 23, the controller produces a signal and the control device starts the next operation in which further water is supplied to the keg 1 .to rinse away the remaining traces of detergent. After a predetermined time the water supply is stopped and the remaining water in the keg 1 is discharged by a further supply of steam. When the detector 21 detects that no further water is passing through the outlet duct 18, the control device is allowed to initiate the final operation. The steam supply is shut-off and the head 3 is retracted from the neck 2 of the keg 1. The keg 1 is then removed to a filling machine and a further keg is brought in to undergo the same washing cycle.

I claim:

1. In a machine for automatically washing beer kegs and like containers having means defining an opening in said container, said machine comprising a head, means for applying said head to said opening, said head including means defining an inlet passage for the supply of washing liquid to said container and for the supply of a gaseous venting fluid under pressure and means defining an outlet passage for the removal of said liquid from said container by said gaseous venting fluid, and control means for controlling the supply of said liquid and said gaseous venting fluid and other operations of said machine, the improvement comprising a liquid detector means in communication with said outlet passage for detecting the presence or absence of liquid in said outlet passage and means operatively connecting said liquid detector means to said control means, whereby after the supply of washing liquid and the subsequent supply of gaseous venting fluid said detector means causes said control means to initiate a further operation of said machine only when said detector means detects the absence of washing liquid in said outlet passage.

2'. A machine as set forth in claim 1 for automatically washing beer kegs and like containers of the kind having means defining an opening in the top of said container and tubular spear means through which beer or other potable liquid is supplied to said container and, subsequently, is forced out by the application of a top gas pressure to said liquid in said container, wherein said machine further comprises means for holding said containers in an inverted position with said opening directed downwardly, and wherein said inlet passage means in said head is arranged to, communicate with the inside of said tubular spear means and said outlet passage means in said head is arranged to communicate with the space within said container outside said tubular spear means.

3. The machine as set forth in claim 1 wherein said liquid detector means comprises a pair of electrical probes which project into said outlet passage, and an electrical circuit which is connected across said two probes and which is sensitive to the electrical conductivity of the fluid in said outlet passage between said probes, said electrical circuit operating said control means to initiate the further operation of said machine only when said electrical circuit detects a change in conductivity between said probes which signifies a change from washing liquid to gaseous venting fluid passing through said outlet passage.

References Cited UNITED STATES PATENTS 1,603,092 10/ 1926 Morden 137392X 3,119,401 1/1964 Merritt et a1 l3457 3,454,018 7/1969 Ruddick 134-166X FOREIGN PATENTS 1,296,837 5/1962 France 134-57 DANIEL BLUM, Primary Examiner US. Cl. X.R. 

